Multi-item batching heuristics for minimization of queueing delays

Queueing delays in complex manufacturing facilities often constitute the major part of manufacturing lead times. Lead times are in turn primary determinants of manufacturing performance since they affect work-in-process inventory levels, safety stock requirements and schedule performance. Similarly, in service contexts, the costs of waiting in queues form an important aspect of service performance. In many manufacturing and in some service facilities, it is possible to control queueing behavior through batching policies. Here a single facility multi-item (multi-class) model relating batching to queueing delays is formulated. Heuristic batching rules are developed, and the relationship of batch size and queue time to system parameters such as setup times, is explored. The heuristics are tested numerically, and found to be very effective.